[deliverable/linux.git] / net / core / flow_dissector.c

#include <linux/skbuff.h>
#include <linux/export.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_vlan.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <linux/igmp.h>
#include <linux/icmp.h>
#include <linux/sctp.h>
#include <linux/dccp.h>
#include <linux/if_tunnel.h>
#include <linux/if_pppox.h>
#include <linux/ppp_defs.h>
#include <net/flow_keys.h>
#include <scsi/fc/fc_fcoe.h>

/* copy saddr & daddr, possibly using 64bit load/store
 * Equivalent to :	flow->src = iph->saddr;
 *			flow->dst = iph->daddr;
 */
static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph)
{
	BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
		     offsetof(typeof(*flow), src) + sizeof(flow->src));
	memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
}

/**
 * __skb_flow_get_ports - extract the upper layer ports and return them
 * @skb: sk_buff to extract the ports from
 * @thoff: transport header offset
 * @ip_proto: protocol for which to get port offset
 * @data: raw buffer pointer to the packet, if NULL use skb->data
 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 *
 * The function will try to retrieve the ports at offset thoff + poff where poff
 * is the protocol port offset returned from proto_ports_offset
 */
__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
			    void *data, int hlen)
{
	int poff = proto_ports_offset(ip_proto);

	if (!data) {
		data = skb->data;
		hlen = skb_headlen(skb);
	}

	if (poff >= 0) {
		__be32 *ports, _ports;

		ports = __skb_header_pointer(skb, thoff + poff,
					     sizeof(_ports), data, hlen, &_ports);
		if (ports)
			return *ports;
	}

	return 0;
}
EXPORT_SYMBOL(__skb_flow_get_ports);

/**
 * __skb_flow_dissect - extract the flow_keys struct and return it
 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 * @data: raw buffer pointer to the packet, if NULL use skb->data
 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 *
 * The function will try to retrieve the struct flow_keys from either the skbuff
 * or a raw buffer specified by the rest parameters
 */
bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow,
			void *data, __be16 proto, int nhoff, int hlen)
{
	u8 ip_proto;

	if (!data) {
		data = skb->data;
		proto = skb->protocol;
		nhoff = skb_network_offset(skb);
		hlen = skb_headlen(skb);
	}

	memset(flow, 0, sizeof(*flow));

again:
	switch (proto) {
	case htons(ETH_P_IP): {
		const struct iphdr *iph;
		struct iphdr _iph;
ip:
		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
		if (!iph || iph->ihl < 5)
			return false;
		nhoff += iph->ihl * 4;

		ip_proto = iph->protocol;
		if (ip_is_fragment(iph))
			ip_proto = 0;

		iph_to_flow_copy_addrs(flow, iph);
		break;
	}
	case htons(ETH_P_IPV6): {
		const struct ipv6hdr *iph;
		struct ipv6hdr _iph;
		__be32 flow_label;

ipv6:
		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
		if (!iph)
			return false;

		ip_proto = iph->nexthdr;
		flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
		flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
		nhoff += sizeof(struct ipv6hdr);

		/* skip the flow label processing if skb is NULL.  The
		 * assumption here is that if there is no skb we are not
		 * looking for flow info as much as we are length.
		 */
		if (!skb)
			break;

		flow_label = ip6_flowlabel(iph);
		if (flow_label) {
			/* Awesome, IPv6 packet has a flow label so we can
			 * use that to represent the ports without any
			 * further dissection.
			 */
			flow->n_proto = proto;
			flow->ip_proto = ip_proto;
			flow->ports = flow_label;
			flow->thoff = (u16)nhoff;

			return true;
		}

		break;
	}
	case htons(ETH_P_8021AD):
	case htons(ETH_P_8021Q): {
		const struct vlan_hdr *vlan;
		struct vlan_hdr _vlan;

		vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
		if (!vlan)
			return false;

		proto = vlan->h_vlan_encapsulated_proto;
		nhoff += sizeof(*vlan);
		goto again;
	}
	case htons(ETH_P_PPP_SES): {
		struct {
			struct pppoe_hdr hdr;
			__be16 proto;
		} *hdr, _hdr;
		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
		if (!hdr)
			return false;
		proto = hdr->proto;
		nhoff += PPPOE_SES_HLEN;
		switch (proto) {
		case htons(PPP_IP):
			goto ip;
		case htons(PPP_IPV6):
			goto ipv6;
		default:
			return false;
		}
	}
	case htons(ETH_P_FCOE):
		flow->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
		/* fall through */
	default:
		return false;
	}

	switch (ip_proto) {
	case IPPROTO_GRE: {
		struct gre_hdr {
			__be16 flags;
			__be16 proto;
		} *hdr, _hdr;

		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
		if (!hdr)
			return false;
		/*
		 * Only look inside GRE if version zero and no
		 * routing
		 */
		if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
			proto = hdr->proto;
			nhoff += 4;
			if (hdr->flags & GRE_CSUM)
				nhoff += 4;
			if (hdr->flags & GRE_KEY)
				nhoff += 4;
			if (hdr->flags & GRE_SEQ)
				nhoff += 4;
			if (proto == htons(ETH_P_TEB)) {
				const struct ethhdr *eth;
				struct ethhdr _eth;

				eth = __skb_header_pointer(skb, nhoff,
							   sizeof(_eth),
							   data, hlen, &_eth);
				if (!eth)
					return false;
				proto = eth->h_proto;
				nhoff += sizeof(*eth);
			}
			goto again;
		}
		break;
	}
	case IPPROTO_IPIP:
		proto = htons(ETH_P_IP);
		goto ip;
	case IPPROTO_IPV6:
		proto = htons(ETH_P_IPV6);
		goto ipv6;
	default:
		break;
	}

	flow->n_proto = proto;
	flow->ip_proto = ip_proto;
	flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen);
	flow->thoff = (u16) nhoff;

	return true;
}
EXPORT_SYMBOL(__skb_flow_dissect);

static u32 hashrnd __read_mostly;
static __always_inline void __flow_hash_secret_init(void)
{
	net_get_random_once(&hashrnd, sizeof(hashrnd));
}

static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c)
{
	__flow_hash_secret_init();
	return jhash_3words(a, b, c, hashrnd);
}

static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
{
	u32 hash;

	/* get a consistent hash (same value on both flow directions) */
	if (((__force u32)keys->dst < (__force u32)keys->src) ||
	    (((__force u32)keys->dst == (__force u32)keys->src) &&
	     ((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) {
		swap(keys->dst, keys->src);
		swap(keys->port16[0], keys->port16[1]);
	}

	hash = __flow_hash_3words((__force u32)keys->dst,
				  (__force u32)keys->src,
				  (__force u32)keys->ports);
	if (!hash)
		hash = 1;

	return hash;
}

u32 flow_hash_from_keys(struct flow_keys *keys)
{
	return __flow_hash_from_keys(keys);
}
EXPORT_SYMBOL(flow_hash_from_keys);

/*
 * __skb_get_hash: calculate a flow hash based on src/dst addresses
 * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 * if hash is a canonical 4-tuple hash over transport ports.
 */
void __skb_get_hash(struct sk_buff *skb)
{
	struct flow_keys keys;

	if (!skb_flow_dissect(skb, &keys))
		return;

	if (keys.ports)
		skb->l4_hash = 1;

	skb->sw_hash = 1;

	skb->hash = __flow_hash_from_keys(&keys);
}
EXPORT_SYMBOL(__skb_get_hash);

/*
 * Returns a Tx hash based on the given packet descriptor a Tx queues' number
 * to be used as a distribution range.
 */
u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
		  unsigned int num_tx_queues)
{
	u32 hash;
	u16 qoffset = 0;
	u16 qcount = num_tx_queues;

	if (skb_rx_queue_recorded(skb)) {
		hash = skb_get_rx_queue(skb);
		while (unlikely(hash >= num_tx_queues))
			hash -= num_tx_queues;
		return hash;
	}

	if (dev->num_tc) {
		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
		qoffset = dev->tc_to_txq[tc].offset;
		qcount = dev->tc_to_txq[tc].count;
	}

	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
}
EXPORT_SYMBOL(__skb_tx_hash);

u32 __skb_get_poff(const struct sk_buff *skb, void *data,
		   const struct flow_keys *keys, int hlen)
{
	u32 poff = keys->thoff;

	switch (keys->ip_proto) {
	case IPPROTO_TCP: {
		const struct tcphdr *tcph;
		struct tcphdr _tcph;

		tcph = __skb_header_pointer(skb, poff, sizeof(_tcph),
					    data, hlen, &_tcph);
		if (!tcph)
			return poff;

		poff += max_t(u32, sizeof(struct tcphdr), tcph->doff * 4);
		break;
	}
	case IPPROTO_UDP:
	case IPPROTO_UDPLITE:
		poff += sizeof(struct udphdr);
		break;
	/* For the rest, we do not really care about header
	 * extensions at this point for now.
	 */
	case IPPROTO_ICMP:
		poff += sizeof(struct icmphdr);
		break;
	case IPPROTO_ICMPV6:
		poff += sizeof(struct icmp6hdr);
		break;
	case IPPROTO_IGMP:
		poff += sizeof(struct igmphdr);
		break;
	case IPPROTO_DCCP:
		poff += sizeof(struct dccp_hdr);
		break;
	case IPPROTO_SCTP:
		poff += sizeof(struct sctphdr);
		break;
	}

	return poff;
}

/* skb_get_poff() returns the offset to the payload as far as it could
 * be dissected. The main user is currently BPF, so that we can dynamically
 * truncate packets without needing to push actual payload to the user
 * space and can analyze headers only, instead.
 */
u32 skb_get_poff(const struct sk_buff *skb)
{
	struct flow_keys keys;

	if (!skb_flow_dissect(skb, &keys))
		return 0;

	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
}

static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
{
#ifdef CONFIG_XPS
	struct xps_dev_maps *dev_maps;
	struct xps_map *map;
	int queue_index = -1;

	rcu_read_lock();
	dev_maps = rcu_dereference(dev->xps_maps);
	if (dev_maps) {
		map = rcu_dereference(
		    dev_maps->cpu_map[raw_smp_processor_id()]);
		if (map) {
			if (map->len == 1)
				queue_index = map->queues[0];
			else
				queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
									   map->len)];
			if (unlikely(queue_index >= dev->real_num_tx_queues))
				queue_index = -1;
		}
	}
	rcu_read_unlock();

	return queue_index;
#else
	return -1;
#endif
}

static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
{
	struct sock *sk = skb->sk;
	int queue_index = sk_tx_queue_get(sk);

	if (queue_index < 0 || skb->ooo_okay ||
	    queue_index >= dev->real_num_tx_queues) {
		int new_index = get_xps_queue(dev, skb);
		if (new_index < 0)
			new_index = skb_tx_hash(dev, skb);

		if (queue_index != new_index && sk &&
		    rcu_access_pointer(sk->sk_dst_cache))
			sk_tx_queue_set(sk, new_index);

		queue_index = new_index;
	}

	return queue_index;
}

struct netdev_queue *netdev_pick_tx(struct net_device *dev,
				    struct sk_buff *skb,
				    void *accel_priv)
{
	int queue_index = 0;

	if (dev->real_num_tx_queues != 1) {
		const struct net_device_ops *ops = dev->netdev_ops;
		if (ops->ndo_select_queue)
			queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
							    __netdev_pick_tx);
		else
			queue_index = __netdev_pick_tx(dev, skb);

		if (!accel_priv)
			queue_index = netdev_cap_txqueue(dev, queue_index);
	}

	skb_set_queue_mapping(skb, queue_index);
	return netdev_get_tx_queue(dev, queue_index);
}
Commit	Line	Data
0744dd00	1	#include <linux/skbuff.h>
c452ed70	2	#include <linux/export.h>
0744dd00 ED	3	#include <linux/ip.h>
	4	#include <linux/ipv6.h>
	5	#include <linux/if_vlan.h>
	6	#include <net/ip.h>
ddbe5032	7	#include <net/ipv6.h>
f77668dc DB	8	#include <linux/igmp.h>
	9	#include <linux/icmp.h>
	10	#include <linux/sctp.h>
	11	#include <linux/dccp.h>
0744dd00 ED	12	#include <linux/if_tunnel.h>
	13	#include <linux/if_pppox.h>
	14	#include <linux/ppp_defs.h>
	15	#include <net/flow_keys.h>
56193d1b	16	#include <scsi/fc/fc_fcoe.h>
0744dd00	17
4d77d2b5 ED	18	/* copy saddr & daddr, possibly using 64bit load/store
	19	* Equivalent to : flow->src = iph->saddr;
	20	* flow->dst = iph->daddr;
	21	*/
	22	static void iph_to_flow_copy_addrs(struct flow_keys flow, const struct iphdr iph)
	23	{
	24	BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
	25	offsetof(typeof(*flow), src) + sizeof(flow->src));
	26	memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
	27	}
0744dd00	28
357afe9c	29	/**
6451b3f5 WC	30	* __skb_flow_get_ports - extract the upper layer ports and return them
6451b3f5 WC	31	* @skb: sk_buff to extract the ports from
357afe9c NA	32	* @thoff: transport header offset
357afe9c NA	33	* @ip_proto: protocol for which to get port offset
6451b3f5 WC	34	* @data: raw buffer pointer to the packet, if NULL use skb->data
6451b3f5 WC	35	* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
357afe9c NA	36	*
	37	* The function will try to retrieve the ports at offset thoff + poff where poff
	38	* is the protocol port offset returned from proto_ports_offset
	39	*/
690e36e7 DM	40	__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
690e36e7 DM	41	void *data, int hlen)
357afe9c NA	42	{
	43	int poff = proto_ports_offset(ip_proto);
	44
690e36e7 DM	45	if (!data) {
	46	data = skb->data;
	47	hlen = skb_headlen(skb);
	48	}
	49
357afe9c NA	50	if (poff >= 0) {
	51	__be32 *ports, _ports;
	52
690e36e7 DM	53	ports = __skb_header_pointer(skb, thoff + poff,
690e36e7 DM	54	sizeof(_ports), data, hlen, &_ports);
357afe9c NA	55	if (ports)
	56	return *ports;
	57	}
	58
	59	return 0;
	60	}
690e36e7	61	EXPORT_SYMBOL(__skb_flow_get_ports);
357afe9c	62
453a940e WC	63	/**
	64	* __skb_flow_dissect - extract the flow_keys struct and return it
	65	* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
	66	* @data: raw buffer pointer to the packet, if NULL use skb->data
	67	* @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
	68	* @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
	69	* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
	70	*
	71	* The function will try to retrieve the struct flow_keys from either the skbuff
	72	* or a raw buffer specified by the rest parameters
	73	*/
	74	bool __skb_flow_dissect(const struct sk_buff skb, struct flow_keys flow,
	75	void *data, __be16 proto, int nhoff, int hlen)
0744dd00	76	{
0744dd00	77	u8 ip_proto;
0744dd00	78
690e36e7 DM	79	if (!data) {
690e36e7 DM	80	data = skb->data;
453a940e WC	81	proto = skb->protocol;
453a940e WC	82	nhoff = skb_network_offset(skb);
690e36e7 DM	83	hlen = skb_headlen(skb);
	84	}
	85
0744dd00 ED	86	memset(flow, 0, sizeof(*flow));
	87
	88	again:
	89	switch (proto) {
2b8837ae	90	case htons(ETH_P_IP): {
0744dd00 ED	91	const struct iphdr *iph;
	92	struct iphdr _iph;
	93	ip:
690e36e7	94	iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
6f092343	95	if (!iph \|\| iph->ihl < 5)
0744dd00	96	return false;
3797d3e8	97	nhoff += iph->ihl * 4;
0744dd00	98
3797d3e8	99	ip_proto = iph->protocol;
0744dd00 ED	100	if (ip_is_fragment(iph))
0744dd00 ED	101	ip_proto = 0;
3797d3e8	102
4d77d2b5	103	iph_to_flow_copy_addrs(flow, iph);
0744dd00 ED	104	break;
0744dd00 ED	105	}
2b8837ae	106	case htons(ETH_P_IPV6): {
0744dd00 ED	107	const struct ipv6hdr *iph;
0744dd00 ED	108	struct ipv6hdr _iph;
19469a87 TH	109	__be32 flow_label;
19469a87 TH	110
0744dd00	111	ipv6:
690e36e7	112	iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
0744dd00 ED	113	if (!iph)
	114	return false;
	115
	116	ip_proto = iph->nexthdr;
ddbe5032 ED	117	flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
ddbe5032 ED	118	flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
0744dd00	119	nhoff += sizeof(struct ipv6hdr);
19469a87	120
56193d1b AD	121	/* skip the flow label processing if skb is NULL. The
	122	* assumption here is that if there is no skb we are not
	123	* looking for flow info as much as we are length.
	124	*/
	125	if (!skb)
	126	break;
	127
19469a87 TH	128	flow_label = ip6_flowlabel(iph);
	129	if (flow_label) {
	130	/* Awesome, IPv6 packet has a flow label so we can
	131	* use that to represent the ports without any
	132	* further dissection.
	133	*/
	134	flow->n_proto = proto;
	135	flow->ip_proto = ip_proto;
	136	flow->ports = flow_label;
	137	flow->thoff = (u16)nhoff;
	138
	139	return true;
	140	}
	141
0744dd00 ED	142	break;
0744dd00 ED	143	}
2b8837ae JP	144	case htons(ETH_P_8021AD):
2b8837ae JP	145	case htons(ETH_P_8021Q): {
0744dd00 ED	146	const struct vlan_hdr *vlan;
	147	struct vlan_hdr _vlan;
	148
690e36e7	149	vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
0744dd00 ED	150	if (!vlan)
	151	return false;
	152
	153	proto = vlan->h_vlan_encapsulated_proto;
	154	nhoff += sizeof(*vlan);
	155	goto again;
	156	}
2b8837ae	157	case htons(ETH_P_PPP_SES): {
0744dd00 ED	158	struct {
	159	struct pppoe_hdr hdr;
	160	__be16 proto;
	161	} *hdr, _hdr;
690e36e7	162	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
0744dd00 ED	163	if (!hdr)
	164	return false;
	165	proto = hdr->proto;
	166	nhoff += PPPOE_SES_HLEN;
	167	switch (proto) {
2b8837ae	168	case htons(PPP_IP):
0744dd00	169	goto ip;
2b8837ae	170	case htons(PPP_IPV6):
0744dd00 ED	171	goto ipv6;
	172	default:
	173	return false;
	174	}
	175	}
56193d1b AD	176	case htons(ETH_P_FCOE):
	177	flow->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
	178	/* fall through */
0744dd00 ED	179	default:
	180	return false;
	181	}
	182
	183	switch (ip_proto) {
	184	case IPPROTO_GRE: {
	185	struct gre_hdr {
	186	__be16 flags;
	187	__be16 proto;
	188	} *hdr, _hdr;
	189
690e36e7	190	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
0744dd00 ED	191	if (!hdr)
	192	return false;
	193	/*
	194	* Only look inside GRE if version zero and no
	195	* routing
	196	*/
	197	if (!(hdr->flags & (GRE_VERSION\|GRE_ROUTING))) {
	198	proto = hdr->proto;
	199	nhoff += 4;
	200	if (hdr->flags & GRE_CSUM)
	201	nhoff += 4;
	202	if (hdr->flags & GRE_KEY)
	203	nhoff += 4;
	204	if (hdr->flags & GRE_SEQ)
	205	nhoff += 4;
e1733de2 MD	206	if (proto == htons(ETH_P_TEB)) {
	207	const struct ethhdr *eth;
	208	struct ethhdr _eth;
	209
690e36e7 DM	210	eth = __skb_header_pointer(skb, nhoff,
	211	sizeof(_eth),
	212	data, hlen, &_eth);
e1733de2 MD	213	if (!eth)
	214	return false;
	215	proto = eth->h_proto;
	216	nhoff += sizeof(*eth);
	217	}
0744dd00 ED	218	goto again;
	219	}
	220	break;
	221	}
	222	case IPPROTO_IPIP:
fca41895 TH	223	proto = htons(ETH_P_IP);
fca41895 TH	224	goto ip;
b438f940 TH	225	case IPPROTO_IPV6:
	226	proto = htons(ETH_P_IPV6);
	227	goto ipv6;
0744dd00 ED	228	default:
	229	break;
	230	}
	231
e0f31d84	232	flow->n_proto = proto;
0744dd00	233	flow->ip_proto = ip_proto;
690e36e7	234	flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen);
8ed78166 DB	235	flow->thoff = (u16) nhoff;
8ed78166 DB	236
0744dd00 ED	237	return true;
0744dd00 ED	238	}
690e36e7	239	EXPORT_SYMBOL(__skb_flow_dissect);
441d9d32 CW	240
441d9d32 CW	241	static u32 hashrnd __read_mostly;
66415cf8 HFS	242	static __always_inline void __flow_hash_secret_init(void)
	243	{
	244	net_get_random_once(&hashrnd, sizeof(hashrnd));
	245	}
	246
	247	static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c)
	248	{
	249	__flow_hash_secret_init();
	250	return jhash_3words(a, b, c, hashrnd);
	251	}
	252
5ed20a68 TH	253	static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
	254	{
	255	u32 hash;
	256
	257	/* get a consistent hash (same value on both flow directions) */
	258	if (((__force u32)keys->dst < (__force u32)keys->src) \|\|
	259	(((__force u32)keys->dst == (__force u32)keys->src) &&
	260	((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) {
	261	swap(keys->dst, keys->src);
	262	swap(keys->port16[0], keys->port16[1]);
	263	}
	264
	265	hash = __flow_hash_3words((__force u32)keys->dst,
	266	(__force u32)keys->src,
	267	(__force u32)keys->ports);
	268	if (!hash)
	269	hash = 1;
	270
	271	return hash;
	272	}
	273
	274	u32 flow_hash_from_keys(struct flow_keys *keys)
	275	{
	276	return __flow_hash_from_keys(keys);
	277	}
	278	EXPORT_SYMBOL(flow_hash_from_keys);
	279
441d9d32	280	/*
3958afa1	281	* __skb_get_hash: calculate a flow hash based on src/dst addresses
61b905da TH	282	* and src/dst port numbers. Sets hash in skb to non-zero hash value
61b905da TH	283	* on success, zero indicates no valid hash. Also, sets l4_hash in skb
441d9d32 CW	284	* if hash is a canonical 4-tuple hash over transport ports.
441d9d32 CW	285	*/
3958afa1	286	void __skb_get_hash(struct sk_buff *skb)
441d9d32 CW	287	{
441d9d32 CW	288	struct flow_keys keys;
441d9d32 CW	289
	290	if (!skb_flow_dissect(skb, &keys))
	291	return;
	292
	293	if (keys.ports)
61b905da	294	skb->l4_hash = 1;
441d9d32	295
a3b18ddb TH	296	skb->sw_hash = 1;
a3b18ddb TH	297
5ed20a68	298	skb->hash = __flow_hash_from_keys(&keys);
441d9d32	299	}
3958afa1	300	EXPORT_SYMBOL(__skb_get_hash);
441d9d32 CW	301
	302	/*
	303	* Returns a Tx hash based on the given packet descriptor a Tx queues' number
	304	* to be used as a distribution range.
	305	*/
0e001614	306	u16 __skb_tx_hash(const struct net_device dev, struct sk_buff skb,
441d9d32 CW	307	unsigned int num_tx_queues)
	308	{
	309	u32 hash;
	310	u16 qoffset = 0;
	311	u16 qcount = num_tx_queues;
	312
	313	if (skb_rx_queue_recorded(skb)) {
	314	hash = skb_get_rx_queue(skb);
	315	while (unlikely(hash >= num_tx_queues))
	316	hash -= num_tx_queues;
	317	return hash;
	318	}
	319
	320	if (dev->num_tc) {
	321	u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
	322	qoffset = dev->tc_to_txq[tc].offset;
	323	qcount = dev->tc_to_txq[tc].count;
	324	}
	325
8fc54f68	326	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
441d9d32 CW	327	}
	328	EXPORT_SYMBOL(__skb_tx_hash);
	329
56193d1b AD	330	u32 __skb_get_poff(const struct sk_buff skb, void data,
56193d1b AD	331	const struct flow_keys *keys, int hlen)
f77668dc	332	{
56193d1b	333	u32 poff = keys->thoff;
f77668dc	334
56193d1b	335	switch (keys->ip_proto) {
f77668dc DB	336	case IPPROTO_TCP: {
	337	const struct tcphdr *tcph;
	338	struct tcphdr _tcph;
	339
56193d1b AD	340	tcph = __skb_header_pointer(skb, poff, sizeof(_tcph),
56193d1b AD	341	data, hlen, &_tcph);
f77668dc DB	342	if (!tcph)
	343	return poff;
	344
	345	poff += max_t(u32, sizeof(struct tcphdr), tcph->doff * 4);
	346	break;
	347	}
	348	case IPPROTO_UDP:
	349	case IPPROTO_UDPLITE:
	350	poff += sizeof(struct udphdr);
	351	break;
	352	/* For the rest, we do not really care about header
	353	* extensions at this point for now.
	354	*/
	355	case IPPROTO_ICMP:
	356	poff += sizeof(struct icmphdr);
	357	break;
	358	case IPPROTO_ICMPV6:
	359	poff += sizeof(struct icmp6hdr);
	360	break;
	361	case IPPROTO_IGMP:
	362	poff += sizeof(struct igmphdr);
	363	break;
	364	case IPPROTO_DCCP:
	365	poff += sizeof(struct dccp_hdr);
	366	break;
	367	case IPPROTO_SCTP:
	368	poff += sizeof(struct sctphdr);
	369	break;
	370	}
	371
	372	return poff;
	373	}
	374
56193d1b AD	375	/* skb_get_poff() returns the offset to the payload as far as it could
	376	* be dissected. The main user is currently BPF, so that we can dynamically
	377	* truncate packets without needing to push actual payload to the user
	378	* space and can analyze headers only, instead.
	379	*/
	380	u32 skb_get_poff(const struct sk_buff *skb)
	381	{
	382	struct flow_keys keys;
	383
	384	if (!skb_flow_dissect(skb, &keys))
	385	return 0;
	386
	387	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
	388	}
	389
441d9d32 CW	390	static inline int get_xps_queue(struct net_device dev, struct sk_buff skb)
	391	{
	392	#ifdef CONFIG_XPS
	393	struct xps_dev_maps *dev_maps;
	394	struct xps_map *map;
	395	int queue_index = -1;
	396
	397	rcu_read_lock();
	398	dev_maps = rcu_dereference(dev->xps_maps);
	399	if (dev_maps) {
	400	map = rcu_dereference(
	401	dev_maps->cpu_map[raw_smp_processor_id()]);
	402	if (map) {
	403	if (map->len == 1)
	404	queue_index = map->queues[0];
0e001614	405	else
8fc54f68 DB	406	queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
8fc54f68 DB	407	map->len)];
441d9d32 CW	408	if (unlikely(queue_index >= dev->real_num_tx_queues))
	409	queue_index = -1;
	410	}
	411	}
	412	rcu_read_unlock();
	413
	414	return queue_index;
	415	#else
	416	return -1;
	417	#endif
	418	}
	419
99932d4f	420	static u16 __netdev_pick_tx(struct net_device dev, struct sk_buff skb)
441d9d32 CW	421	{
	422	struct sock *sk = skb->sk;
	423	int queue_index = sk_tx_queue_get(sk);
	424
	425	if (queue_index < 0 \|\| skb->ooo_okay \|\|
	426	queue_index >= dev->real_num_tx_queues) {
	427	int new_index = get_xps_queue(dev, skb);
	428	if (new_index < 0)
	429	new_index = skb_tx_hash(dev, skb);
	430
702821f4 ED	431	if (queue_index != new_index && sk &&
702821f4 ED	432	rcu_access_pointer(sk->sk_dst_cache))
50d1784e	433	sk_tx_queue_set(sk, new_index);
441d9d32 CW	434
	435	queue_index = new_index;
	436	}
	437
	438	return queue_index;
	439	}
441d9d32 CW	440
441d9d32 CW	441	struct netdev_queue netdev_pick_tx(struct net_device dev,
f663dd9a JW	442	struct sk_buff *skb,
f663dd9a JW	443	void *accel_priv)
441d9d32 CW	444	{
	445	int queue_index = 0;
	446
	447	if (dev->real_num_tx_queues != 1) {
	448	const struct net_device_ops *ops = dev->netdev_ops;
	449	if (ops->ndo_select_queue)
99932d4f DB	450	queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
99932d4f DB	451	__netdev_pick_tx);
441d9d32 CW	452	else
441d9d32 CW	453	queue_index = __netdev_pick_tx(dev, skb);
f663dd9a JW	454
f663dd9a JW	455	if (!accel_priv)
b9507bda	456	queue_index = netdev_cap_txqueue(dev, queue_index);
441d9d32 CW	457	}
	458
	459	skb_set_queue_mapping(skb, queue_index);
	460	return netdev_get_tx_queue(dev, queue_index);
	461	}